This is a multi-center, phase Ib/ II study (two parts) with patients that had recurrent glioblastoma multiforme. The first part (phase Ib) was to investigate the maximum tolerated dose/Recommended phase ll dose (MTD/RP2D) of once daily buparlisib in combination with every-three-week carboplatin or buparlisib once daily in combination with every-six-week lomustine (CCNU) using a Bayesian model. Once MTD/ RP2D is established in either of the 2 arms, the corresponding phase II portion of the study was to start. Phase II was to assess the treatment effect of buparlisib in combination with carboplatin in terms of Progression Free Survival (PFS) and was to compare the treatment effect of buparlisib with lomustine versus lomustine plus placebo in terms of PFS.